Vania



C. C. WHITTAKER. SYSTEM 0F CONTROL.

APPLICATION FILI-:n Dc.2o.'I9I6.

Patented Dec. 30, 1919.

4 SHEETS-SHEET l.

@QS Y WITNESSES: 4

BY wot/6% WM TTORNEY C. C. WHITTAKER.

SYSTEM 0F CONTROL.

APPLICATION man DEc.2o. 191e.

Patented Dec. 30, 1919.

4 SHEETS-SHEET 2.

INVENTOR bar/e5@ W/ua keg WITNESSES:

TTO'RNEY c. c. WHITTAKER.

SYSTEM 0F CONTROL.

APPLICATION FILED 050.20. 1916.

1,326,315. Patented Dec. 30,1919.

4 SHEETS-SHEET 3.

Acceleration 52m/ence of Jwiches.

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Trans/'fion .Para/le oo 0 O O O Parel/el 0 000000000 00000000 eres. 0 000 I Il C. C. WHITTAKER.

SYSTEM 0F CONTROL.

APPLICATION mzu'nwzo. |916.

Patented Dee. 30,1919.

4 SHEETS*SHEET 4.

INVENTOR Char/ea C W/7/7qer ATTORNEY WITNEssEs;

miran srarns ramena carica.

CHARLES c. wnrrrfinnnon WILKINsBUnG, Pnnnsrnvranra assrenon `To'wnsrms- Honsnnnnornrc AND MANUFACTURING contrastar, a consonancia or 'PENNSYL- vANIa Application led December To. all whom it lmay concern:

Be it known that I, CHARLES C. WHIT- TAKER, a citizen of the United States, and a resident'of -llilkinsburg, in the county of Allegheny and, State of Pennsylvania, have invented a new and useful Improvement in "Systems o'f'Control, of whichfthe following is a specication.

Myinvention relatesV to systems of control Vand especially to regenerative systems for electric railway motors and .thelilreV In a co-pending application of ILM. Perkins, Serial No. 83,7241,e filed Marchy 13, 1916, patented May 28,1918, No. 1,268,052, and assigned to the Westinghouse :Electric '8e Manufacturing Company, .is set-forth a regenerative control lsys'tem' embodying a plurality of separately-excited momentumdriven machines that are adapted for either parallel or series operation" in accordance with the initialr regenerative speed, and a .selective relay device. for automatically initially connecting the machines in either parallel or series relation by reasonof the voltage thatv'is generated by the momentumdriven armatures, whichV voltage is dependent upon the vehicle speed.

As is more or less customary, a variable resistor is initially included in circuit with 'fthe machines in the. above-mentioned system,

and it is desirable that such resistor be gradually excluded from circuit in ac- -cordance with the operation of a limit switch that is energized by the regenerated current. However, it has been found that the selective relay device operates yto connect the machine to the supply circuit when a relatively weak field-excitationobtains. rihus, the resistor short-circuiting switches are rapidly -closed before the regenerated 'the momentum-driven machines.

AMore specifically stated, it is the object of Specification of Letters Patent.

SYSTEM OF CONTROL.

2G, 1916. Serial No.V 138,032.

my .invention to provide, in connection with .the previously-recited variable resistorand limit switch, a relay device that is energized in accordance with the field-winding current lfor renderingv the limit switch inoperatve to close the resistor. short-circuiting .switches until the field-winding 4current has been built-,upby an auxiliary .source ofrenergy to the desired value.

My invention may .bestbeunderstood by reference to. the .accompanying drawings, .wherein Figure 1 is a diagrammatic view .of l.the main circuits of al system. ofcontrohembodying my invention; F ig. 2 isa diagram- .matic view `of .the auxiliary, governing circuits fonmanipulating-,the various circuitsivitchesthat are illustrated ingFigigl;

8 and Fig.Y a. are sequence charts ofjwell- Aflmown fornrforzindicating the desiredrorder 'of1operationofthe various switchesfduring the accelerating ,and regenerative .,.periods, respectively; Fig. 5 is a`detailed. diagram matic view of one of the complete' maincircuit switches that are shown vin 4Fig. 1;

and Fig. 6:and Fig. 7 are simplifiedl Views ci the accelerating and theregenerati-ve circuit connections, respectively.

Referring to 1F ig. 1, the systemlvshown comprises :a f plurality of .-.suitable i supplycircuit conductors .respectively in -arlied'1 4 {Trolleg.-Y and Ground; a plurality offdynamoelectric machinesrespectively having armatures A1 and A2 and lield-magnetwindings and F'Zof the series type; .a reversing switch lB-S,1-l1ere shown conventionally, but

preferabiy of a familiar electrically-con- .troiled type, as indicated in. the auxiliary i circuits of-Fig. 2, for reversing the electrical relations of theI several main armatures and ,Patented Dec.' 3o, 1919. y

eld windings;; amain-circuitdnsistor 4AE1 .with which fs; associated, aplurality; ofsuitshort-.circuiting switches R1, R2, R3 and c. secondmain-circuit resistor AR2 with which is similarly associated a plurality of 'itches iti-R1, RvR-2, HB3 and RIM; a third 4Inoto'rl armature.

motor oran equivalent motor-generatori set closing the -valve 13, as described in' connectain of the main-motor, and also the auxiliary, circuits during both the accelerating and regenerative periods in accordance with its occupation of the positions marked Acc. and Reg.; a field-circuit controlling device PK of the drum type, having an operating mechanism OM, for varying the active value of a plurality of resistors FR1 and FB2 that are disposed in circuit with the' main eld windings during the regenerative period, as set forth later; a motor-generator or dynamotor D of a familiar type for supplying exciting energy to the main field-winding circuits during the regenerative period; and a relay device RD, which is associated with or exciting-.armature winding G that is preferably disposed u on the same shafts as the rowever,'it will be appreciated that any other suitable type of dynamay bel/employed, ifudesired, and the customary functions of :such a machine, forexample, driving air-compressors and furnishing energy for various auxiliary circuits, 'inay'be utilized, if deemed advisable.

^ l The relayfvdevicel RD is preferably of a familiar Solenoid type, and the actuating coil thereof is connected from the highervoltage terminal of the switch M1 to the lowervoltage terminal of the armature A2.

It will be observed that, when the parallelconnecting switches M1 and G1 are closed, jthe relay device receives the voltage of each of the vparallel-related armatures, while, upon the :closure of the series-connecting switch Jl and the opening of the parallel-connecting switches, the relay device is energized in accordance with the combined voltages of the two sets of armatures, for regenerative purposes to be set forth.

The control device PK comprises a main drum portion MD that is provided with suitable stationary and movable contact members for gradually short-circuiting the field- L i circuit resistors FR1 and FB2 as the drumA with Fig. 2, whereby astep-by-step movement of the PK controller is effected.

The operating mechanism OM is of a familiar type and comprises a pinion-6 that is rigidly secured to the end of the shaft 5 of the PK controller and meshes with a horizontally movable rack member 7, with the ends of which a plurality of pistons Sand 9 are respectively associated. A plurality of suitable operating cylinders 10 and 11 are provided for the pistcnsvS and 9, and a plurality of valve members 12 and 13 are adapted to admit iiuid pressure from any suitable source (not shown) through pipes or passages 14 and 15, respectively, in accordance with predetermined conditions to be described. The valve 12 is normally closed to exclude fluid-pressure from the cylinder 10 and to permit communication of the cylinder with the atmosphere. An actuating coil On is provided for controlling the action of the valve On theother hand, .the valve 13 and an actuating coil Off is supplied for initial unbalanced fluid-pressure conditions are reversed to actuate the pistons toward the right. If it is desired to arrest the controller movement at any point, theoff coil is denergized, and balanced-pressure ccnditions obtain in the two cylinders, thus positively and reliably stopping the controller. To effect return movement, it is merely necessary to denergizeboth coils, whereby the initial unbalanced-pressure conditions are restoredand the pistons are moved to the illustrated positions.

The auxiliary governing system that is shown in Fig. 2 comprises, in addition to the actuating coils of the various switching devices that are illustrated in Fig. 1, a lplurality of interlocking contact members of a familiar type that are illustrated in Fig. 5 in connectionwith the y,switch LS1and the interlocking'drum ID, a master controller MO that is adapted to occupy a plurality of operative positions a to n, when operated in one direction that corresponds to acceleration of the motors, yand a`plurality of operating positions a to 7c', when moved in the opposite direction that corresponds to regeneration of the momentum-driven machines; a master reverser MP of a familiar type; a suitable source of energy, such as a battery B, for energizing the various actuating coils through the master controller C and through a pluralityl of train-line conductors TL, whereby multiple-unit operation of my system maybe readily e'ected,

-as'will be'understood; Aa control relay GR,

for a'purpose to be described; and certain auxiliary contact members of the changeover switch CO, the limit switch L, the fieldwinding current relay 1I, and the relay device RD, which closes certain auxiliary cirnal of the battery B through conductor 20,

' train-line conductor A21, conductor 22, control fingers23 and- 24, which .are bridged by contact'segment 25 of the master controller' in its posit-ion' lva', conductor 126,: .con- 'tact member`i27,"condutor 28 f fand contact member -29 of the master reverser MRin its forward position, conductor *'30, train-line ,conductor 31,'` conductor I32," contact member *337251*l the main reversing jswitclrRS v1n its forward? position, conductors 34, 35 and 36,

the actuatin coil o'fithejswitch LS1 and an interlockffC -iljifcffwhence `circuit is completed 'through-conductors '37,138 and 39,

contact member 40 of the change-over switch CO in its position Aco.,`7conductor 41, trainliue conductor '42,'conductor 43, control in= gers 44 and 45, which are bridged by contact segment 46 of the master controller, conductor'47, train-line conductor -48 and conductor 49 to the negative terminal of the battery B. The switch LS1 is thus closed, as indicated in the sequence chart of Fig. 3.

'A vfurther circuit is established, at this time, fromthe j-contactsegment 25 lof the master controller through conductor 58, contact segment 59,=c'onductor` 60, contact segment 61 and control finger 62 of the various sections of the master controller; conductor 63, train-line conductor 63a, conductor 64, Contact member 65 of the change-over switch CO in its position Acc., conductor 66, interlocks RR4-out and RRQ-out, conductor 67, the actuating coil of the switch J 1, congductor 681and the-interlock LS1-#in to the negative conductor 39. Upon the closure of the switch J1, a holding circuit therefor is formed by interlock Jl-in, which directly connects conductors 66 and'67.

till another circuit is established in position n, of the master controller frozi corr tact segment 25 through control finger 69, conductor 70, train-line onductor 71, conductor 72, interlocks .l1- in and G11-wout, conductors 7 3 and 74, the parallel-connected actuating coils of the switches R1 and Rll, conductor 75 and interlock LS1-in to the negative conductor 39.

Referring temporarily to the mainwcirlcuits that are shownv in Fig. 1,.the;;closure of the various switches that have beenmentioned completes a main circuit=from the trolley through conductor 76, .the Switch LS1, conductors 77 and 78, the armature A1, conductor 81, Contact member I82.0f'vthe changeover switch C0 in itsposition Acc., conductor 83 and certain contactv members of the vreversing-switch Rneld Winding Y lay `1,""reversing-switch JRS, "conductors :100

and 103, Contact member 104.offthe 'change- 'duct'orff105 to* the negative supply-.circuit conductorGround. (SeeFig. 6`.')`-' f leferring again to -Fig`.`12', when-the. master controller MC is actuated :to itsise'cond accelerating :position b, a'circuit is festablished from the positively energized-.contact A vsegment 61, through control linger 106, conductor 107, train`line conductor 108," conductors 109 and 110,interlo`ck7J1-in, conductor 111, the actuating coil'of-wthesw'itch J3,.intcrlock 112-J3-out, conductor 113, interlock Ml-out, interlock LS1-in, conductor 115, contact member COfAcc. and conductor 37 to the negative conductor 89. As soon'as the switchJS is closed, an additional holding circuit therefor is completed from the actuating coil thereof throughinterlock 112-J3-in and conductors 116 fand 1160. to conductor 39, which vadditional circuit employed in connection with certain other resiStor-short-circuiting sWitches, as

.about to be described.

In position c of the'master controller, the contact segment' 25 engages control finger 117, whence circuit is completed through conductor 118, train-line conductor 119, conductors 120 and 121,- thef actuating; fcoilfgof the Switch R2, conductor `122,'interlock 123- R2-out, conductor 124, interlock 125-J3- in, and thence through conductor 113, as previously described. Upon the closure of the switch R2, a holding circuit'therefor is completed from conductor 122, through interlock 123--R2-in, and conductors 126 and 127 to the conductor 116.

ln position d of the master controller, a circuit is completed from the contact -segment 25 through control finger 128, conductor 129, train-line conductor 130, conductors 131 and 132, the actuating coil of the 140, .interlock 141-R2-in, and thence` through' conductor 124, as previously described.

In position f, a further circuit is co1npleted from the contact segment through control finger 142, conductor 143, train-line conductor 144, conductors 145 and 146, the actuating coil of the switch RR3, conductor 147 and interlock 148-R3-in, a common Vholding circuit for the switches R3 and RR3 heilig completed from the interlock 148 through conductor 127to the conductor 116.

In position g,'a circuit isestablished from the contact segment 61 ofthe master controller through control finger 149, conductor .150, train-line conductor 151, conductor 152,

contact member 153 of the change-oven switch CO in'its position Acc., conductors 154,155iand 156, the actuating coils of the switches R4 and RR4,lconductor 157 and interlock LS1- in to the negativel conductor 39. l

In-` position g, the initial energizing cirf cuit l'of the actuating coils of the switches R1 and RRl is also opened after the closure of the switches R4 and RR4, by reason of the disengagement of the control linger 69 from the contact segment 25. Such action, however, does not vary the main-circuitl re- V sistance since direct shunting paths around the main-circuit resistors ARl and AR2 are provided through the switches R4 and RR4, respectively. A n open-main circuit at this time is prevented by the use of a holding circuit including conductors 35, 163, 208 and 209, interlocks R4-out and RR1in and conductor 74 which is connected to the R1 and RR1 switch-actuating coils, thus prevent;l ing the opening of switches R1 and RRl until the closure of switches R4 andRR4.

In position h, the switches R2, RR2, R3 and RR3 are opened by reason of the disengagement of the contact segment 25 from the corresponding control fingers.

To effect initial parallel connection of the motors, the master controller may be moved toward its position i, whereupon, at rst, the contact segment 61 engages control finger 166, whence circuit is completed through conductor 167, train-line conductor 168, conductor 169, contact member 170 of the change-over switch CO in its position Acc., conductor 171, interlocks Rl-out and RR2-out, conductor 172, the parallel-related actuating coils of the switches M1 and G1,

conductor 173, and interlock LS1-in to the negative conductor 39.

Immediately after the closure of the switches just mentioned, the contact segment 61 of the master controller becomes disengaged from the control fingers 62 and 106, thereby denergizing the previously described circuits 'of the actuating coils of the switches J1 and J 3, respectively'. However, the opening of the switch J1 before the closure of the switches M1 and G1 is prevented by an interlocking arrangement simi-A lar to that set forth in connectionwith the switches R4' and RR4, namely, comprising conductors 165 and 175, interlock Ml-out and interlock .I1-in, which is connected directly tothe actuating coil of the switch J 1. Thus, the energization of the J1 actuating coil is maintained through the holding circuit just recited until the switch M1 closes to interrupt .the connection between conductor 175 and interlock J1-in,.

Referring, for the4 time..being, the main circuits that are established in the initial parallel connections v4of the motors that correspond to position ,i of the master .controller may be yset forth: follows:-

from the trolley through the main anmature A1, main field winding Fl, switch R4, and the- :resistor 'ARl, 'as previously described, switch G1, contact member183 of the change-over switch CO lin* tits position Acc., conductor 184 and conductor 103 to the negative supply-circuit conductor Ground, as already traced. The circuit of the other motor is completed from the trolley through conductors 76, 77 and 185, switch M1, the resistor AR2, conductor 186, switch RR4, conductor 93 and then through the otherinotor to ground, as previously described. The motor having the armature A1 and the resistor ARl thus comprise a -circuii-J that is disposed in parallel relation to a circuit including resistor AR2 and the motor having the armature A2.

In position y' (Fig. 2), the contact segment 25 rengagescontrol finger 117, whence circuit is established as previously recited through the actuating coil of the switch' R2, thence through the interlock 123--R2--out, conductors 124 and 177, interlocks M2-in and LS1-in and thence through conductor 115 to the negative battery terminal, as previously described. Upon the closure of the switch R2, the hereinbefore described holding circuit for the actuating coil thereof is again completed.

In the next three positions c, Z and m of the master controller, the control ingers 128, 134 and 142 respectively make Contact with 'the contact segment 25 to effect the closure of switches RR2, R3 and RR3, as previously set forth.

In the nal position n, the contact Vsegment 61 of the master controller engages control nger 178, whenceA circuit is completed through conductor 179, train-line con- ...85 ltoFig'. 1,

ductor 180, conductor 181, interlock Gl-in andlconductors 73 and. 74 to the actuating coils ofthe switches R1 and BB1, in ac cordance with a circuit 'already traced. AAlthough the resistorshort-circuiting switches are manipulated during the parallel opera tion of the motors in'y a dilferentsequence fronti-hat employed during the series acceleration of the mot-ors, it will be observed that'the lchange of sequence is necessary Iby reason ofthe alteredL relations of the maincircuit ,resistors with respect to the motors, and, in either case, the manipulation of the switches is such as to gradually effect acceleration of the motors.

More specifically stated, the switches R1 and BB1 are, initially employed, whereby thef'curre'nt tra-verses the corresponding resistors V'in certain direction'- during' series acceleration; whereas the switches R4 and 3R51 'are employed during the first portion of `parallel acceleration, Aand fthe current traverses the main resistors in the opposite direction. Y'l-lowever, by connecting theE intermediate'switches",'R2 and RSg-for' example, from vintermediate points of? the l resistor ARl to the terminal of the switch R1 that is remote from the armature'AQ, the same sequence of operation of the intermediate switches may be employed during both series and parallel' operation, which -is desirable for manufacturing and commercial reasons. Assuming that'the vehicle is coasting at a relativel highspeed and that it is de sired to e ect regenerative operation of the system, the master controller MC may be actuated to its initial 'regenerative position a', whereupon a circuitlis firstestablishedy from the positive terminal ofthe battery B through conductor 20, train-linev conductor 21, conductor 200, interlocks LS1-out and PK-a, 'the actuating coil-Reg. of the changeover switch CO, contactmember 201 of the change-over switch in its position Acc., conductor 202, train-line conductor 203, conductor 204:, control fingers 205 and 45, which are bridged by contact segment Q06 of the master controller in,I its position a', and thence, through conductor 47, to the negative battery terminal, 'as already described in connection with the motor acceleration. The change-over switch is thus actuated 'to its Aregenerative position Beg., in a well-known marmer.`

The switch LS1 is not closed at this time by reason of the exclusion 'of the contact member CO'-Acc.l from the energizing circuits of its actuating coil.v The closure of the switch LS1 is entirely dependent upon the upward actuation of the relay device RD, which takes place, under certain regenerative conditions, in a manner to be described.

A. further circuit'is established from the corductor 34.: through conductors 163, 208,

209 and 210, control lingers 211 and 212, which are bridged b'ycontact segmentb213. of the interlock drum PID, conductor 2141;.Z contact memberv 215 of thef-change-O'verswitch CO in its position Reg, and co'nducsl tor 154: to the actuating coils of 'theswitches R4 and RRLL', as hereinbe-foredcscribedf A circuit is established simultaneously.' from the contact segment-213 of-the inter lock drum ID through control' finger 216, conductor 217 contact memberf 218of the change-over switch and thence tol-the actuating coils of the switches lVIfLa'nd; G1, as: already traced. -Y

In the meantime, the eldwindin'gsof the 80 main machines are excited by the generatori armature G in accordance with circuits about to be traced, and the voltageofj-themiann momentum-driven armatures is'. thus built up to a point wherethe combinedielfect of the machine speed an'dfield excitation/suf#Y fices toproduce a ,voltage across eachofl the two armatures A1 and A2, or, in' other words," impresses a voltage upon the actuating-coil of the relay device RD,that is preferably: higher than the supply-circuit voltage :by a,"

lpredetermined amount, whereupon, the re lay device is actuated? toI its, upper-position to complete the`circuit ofthe actuating coil of the switch LS1l from the conductor' 361' through the' actuating coil, conductor. 225, auxiliary contact members 226 of*y the relay: device RDy in its upper or closed position,= and conductor 227 to the Vnegatively-connected conductor 37. Upon the closureof the switch LS1, a holding'circuit therefor is formed from conductor 225,'througlig-confl ductor 22.8, interlock LSL-im ilandf'cornduc-i tor 229 to conductor 227, whereby the auxiliary contact members of the relay device 105 RD are bridged, and the device is inop'ori: ative with respect to varyin the circuit con-A nections during the remain er of the regen-l erative operatiom' However, as previously stated, the rel'ay 110 device RD lifts'when only a relatively weak;v field-winding current has been attainedg'andf it is desirable that; the field-'winding current? reach its full vand steady initial value before the' mainv resistor-short-circuitingl switches 115 begin to close. The field-winding current relay 1 accomplishesthe desiredresult, in the following manner: C The auxiliary contact members of the re#- lay'l are connected in series vrelation' with 120 the actuating coils of certain of the resistorshort-circuiting switches, in accordance with, a circuit about to be traced, and, conse-1 quently, such switches cannot beclos'ed'until the relay 1 occupies its upper position, that 125 is, until the desired full initial value of the' feld-winding current obtains.l v i y Upon the closure of' heV switch LS1 and? the actuation of the relay 1, the previouslymentioned interlock completes-the 130 circuits of the actuating coils ofthe switches RR2, R2, R3 -and'RR3, which are respectively ,connected through conductors 220, 121, 221 and 222 to suitable control fingers that .are joinedbya contact member CO-Reg., to which energy is supplied from the conductor 154C through interlocks d'1- out and M2in and conductor ,224. In this case, however, the conductorfll is opencircuited at the change-over switch, and circuit is completed from interlock'LSl-in through contact .members 114C of the limit switch L, contact member 2 of the relay 1, and conductor 1160i to the negative conductor 39. v

Since anappreciable interval of time, approximately one and one-half seconds in a typical=case,'is necessary l-or the desired initial field-winding current from the auxiliarygenerating armature. G to buildup, a Suiiicient regenerated or armature current will havelbeen' established to litt thelimitz switch L, and the remainder of `the, auto-g matic regenerative` operationis governed bythev limit switch, since, once .the field-wind-f ing current relay 1-1 has been raised tol its, closed position, it Vj cannot possibly drop' out. duringthe remaining operation; because each succeedin step of the'eld-regulatingcontroller P Eeffects the traversal o morecurrent through the lield windings andthe actuating-'coil of the relay 1. than the initial relay-lifting value, as will be understood.

My present' invention is of especial value in cases where the initial regenerative speed is higher than the-normal starting value, providing means whereby the system is saved Afrom damage by reason of the sudden use of regenerative braking when a vehicle has attained a high speed-down agrade, for example.. j The 'time required vfor lthe Y relay. device RD` to litt and thereby 'eliect the connection of the machines.- to lthe supplycircuit bears an inverse relation ,to the initial regenerative speed, since the regenerated voltage is vproportional to -the-.p'roduct'of field-winding excitation vand machine speed.- Consequently, in systems not provided with my field-winding current relay 1, itis; possible to begin` regeneration at a high' speed with' a very 'heavy current by the time the full field-windingcurrent has built up, and the resistor-short-circuitingswitches quickly close to maintain or aggravate such undesirable conditions. By theuse of my present invention, however, :after the closure ofthe line switch-LSLand the building up .1 been reduced to' va suitable value,that is,

until the regenerated current decreases sui iciently to allow the normal operation of the limit switch. Thus, thel field-.windingl current relay 1 and the limit switch L act in conjunction to automatically prevent injurious conditions in the system under relatively high-speed" operation.

The progressive closure of the resistorshort-circuiting switches thus occurs a short time after the closure of the switch LS1 and the attainment of a predetermined fieldwinding current, to short-circuit the main resistors ARl and AR2, dependent upon the main armature current. Thus a steady initial regenerated current of a normal value and producino' a suitable retarding effort is automatically obtained.

kReferring temporarily to the main circuitsy Vthat are shown in Fim 1, the. connections that are establishedby the actuation of the change-over switch C() and the closureof the connecting switches just recited mayI be set iforth as follows: one circuit. is completedgplfrom the lower-voltage terminal of the armature A1, througlionductor 81, contact member 187 off the 4change-over switch l(Oin l.its position Reg., conduct-or 86, switch R1, conductor 89, switch G1, con-I conductor 189, field-regulating resistor FR1 and conductors 190 and 191 to the negative supply-circuit vconductor Ground.l .Asim-l ilar circuit for the other motoruis oompletedfrom vthe lower-voltage termi-nalof the armature A2 through conductor 96,? the actuating coil of the limit switchwL, conductors 97 and 192,-contactrmember 193 of the change-over switch, .conductor-194, fieldregulating resistorfFRQ. 4and conductor 195 to the negative' supply-circuit conductor Ground. VThe two .motor armaturesare thus lrespectively connected in seriesrelation with ythe regulating resistors FRl and F R2 across the supply circuit (see Fig. 7).

A further mai-n circuit is established from the Contact member 188 of the changeover switch through conductor'196, contact member197, conductor 83, the eld wind-- ing F1,conductor 84, contact member 196 of the Achange-over switch, conductors 184 and 103, contactfmembersloeagof .the change overA switch in its position Reg., conductor 199,4 the exciting armature Giand conductor 1992t to the conductor 190.- Aisimilar circuitfor the lother eld winding isconr pleted from the conductor 97 through conductor 98, thelield Winding F2, the actuatf ingcoil of the ie'ld-windingcurrent relay 1, conductor 10G-and thence'to conductor 103 and the exciting armature G as just described.' The exciting armature G' is thus connected to excite the main field windings through the resistors FRl and FB2, respectively.. However,l such arrangement of main-circuit, connections forms no material part of my present, llenficm but fully cuit is completed'from the Contact segment 232, which is connected'by conductor 231e to the segment 61y of the master controller, throughlcontrol finger 233, conductor 234, train-line 'conductor 235, conductor 236,

g where'the circuit divides, one branch including-,conductor 237, control linger 238, contact segment 239 andcontrol finger 240 of the interlock drnmD, conductors 241 and 242, the actuatin coil On and conductors 243y and 243a to t e Anegative conductor 39,

and the otherfbranch including conductor 244, control-,ng'ers 245 and`246, which are bridged' byontact -se'e'ginent 247, conductor 248, interlock .G1Tin,1th,e actuating coil Ott', interlock conductor 249, auxiliary contact vmembers. 250, of` the llimit 'switch L in its loweror operative; position, and thence through conductor 24/3aV'to ,the negative conductor 39'. Inasmuch` as the two actuating coils Onand O of the PKl controller are simultaneously energized, forward movementiof the .co,ntrollerL to its position b occurs .in accordance withthe principles already set forth.

Inpposition of the interlock drum, the circuit ofgthe actuating coil On is maintained. byffthe engagement of the control finger 238 with the contact segment 239, while the .controllinger 245 becomes disengaged from the contact segment 247, thereby denergizing fthe actuating coil Off and, consequently, e'ecting the previously-de-d scribed .balanced-pressure conditions in the operating., mechanism OM to 4,positively and reliably stopthe PK controller in position. fi. I Y Y In position c of the master controller, the contact, segment 232 engages control finger '166, whence circuit is completed through conductor 167, train-line conductor 168, conductor 169, contact segment 251 of the change-over switch, conductor 251e and control finger 252r which is connected to contact segment 247 of the interlock drum ID in position b thereof.` The two actuating coils On and Oi are thus again simultaneously energized and the PK controller is actuated to its position c, whereupon the control finger 252 is disconnected from the contact segment 247, while the contact segment 239 engages another control finger that corresponds to control linger 252 and thus maintains the energization of the On actuating coil.

ln position cl', contact segment 232 engages control finger 149, whence circuit is completed through conductor 150, train-line conductor 151, conductor 152, contact member 253 of the change-over switch, .conductor 253e and control linger 254, which engages contact segment 247 of the interlock drum in position c and thus permits movement of the drum in the manner already described as lfar as position d.

ln position e of the master controller, a control finger 255 engages the Contact segment 232, whence circuit is completed through conductor 256, train-line conductor 257, conductor 258, Contact member 2595of the change-over switch CO, conductor 260 and control finger 261, which engages the contact segment 247 of the interlock drum -in position d and thus permits movement of the drum to position c, which corresponds te the last parallel pos'tion of the regenerating armatures. i i

It should be observed .that thelimit switch L may or niay"not' be'employedpthat is to say, the master controllerg' may be manipulatedby the train operator. in such manner that'the limit switch will not be actuated, but under ordinary braking conditions, the limit switch is preferably employed, so that, when the machine current exceeds, a predetermined value,"^the limit switch L lifts to temporarily interrupt the circuitof the actuating coil Off and thus ,arrest the movement of the controller PK. It will be understood that, wheny the limit switch is utilized, the master controller may be initially actuated to its positions e or lo', and the controllervr PK willthen advance fromY notch to notch yin accordance with'the action'of theliinit switchn L, as is familiar practice.'

. It the master controller MC is moved' t0.- ward its initial series position f,a' lcircilit is first established from the contact segment A232 through control :finger 26.7, coniro ductor 26,8, train-line conductor 269, Aconductors 270 Aand 27,1Y aiidcontrol inger272 which engages thecontact'segment '239f'of the interlock drumY and,l,'conjsequently,'main tains the energize-tio'n' y of the actuating coil On during thel transitional movement ot the controller PK. A new "circuit forisimilarl'y maintaining the Venergi'zation'pit the :coil circuit comprises controliin'ger 2 96'wliich engages Contact V'segnnint'[232, conductor' 297, train-line conductor 298, conductor 299. and control finger 300 which .makes Acontact with segment 247 until just before position f of the interlock vdrum ID, is reached. L

The control fingers 263 and 264 are also bridged by contact segment 273 between the positions` e and f. of the controller PK,I thus bridging the stationary contact inemiin iso

bers of the limit switch L and serving to maintain the actuating`coil Off energized to insure the movement of the controller PK to its initial series position f.

As soon as the controller PK passes beyond its position e, the contact segment 213 engages control finger 274, whence circuit is completed through conductor 275 contact member 276 of the change-over switch CO, where thecircuit divides, one branch including conductor 66, interlocks Rll-in and RR2-out, since the contact segment 232 disengages the corresponding control iingers of the master controller during the movement thereof to position f, and thence through conductor 67 to the actuating coil of the switch J 1, as previously set forth, and the other branch including conductor 278, interlock Gl-out as soon as the switch G1 has opened, as about to be set forth, interlock J1-in and conductor 278a to the contact member 223-CO-Reg., thereby effecting the progressive .closure of switches HB2, R2, R3 and RRS.

The switch J 3 is also closed at this time by reason of the completion of a circuit from the interlock 223--CO-Reg., through conductors 219, 110, interlock .I1- in and conductor 111, whence circuitis'completed in accordance with circuits 4already traced..v In addition, a circuit is completed from lthe positively energized conductor 163, through Vinterlocks BB3-in, (lO-Reg., and J1-'in and conductor 156 through the actuating coils of the switches R4 and RR4, as previously described.

The initial coil-energizing circuits of the switches M1, andv G1 are also opened by reason of the disengagement of the contact segment 232 from the corresponding'l control Iinger 166 during the transitional movement of the lmaster controller, although the opening of these switches is prevented until the switch 1 is closed, by reason of an interlocking arrangement similar to that hereinbefore set forth in connection with, the transitonnrom series to parallel acceleration of the motors, such interlocking arrangement comprising the positively' e'n- 50 ergized conductor. .165, inter-locks I1-out and Ml-in andconductors 277 and 172 tov the actuatingcoils of theswitches M1 and G1, thus insuring that the switch J1 shallbe closed beforethegholding circuit just described for the switchesMl and G1 is interrupted bythe exclusion of the interlock J1out upon the closure of the switch J 1.

As soon as the master controller reaches its initial series position f', one circuit is completed from lthe contact segment 232 through control finger 279, conductor 280, train-line conductor 281, conductor 282, ac-

tuating coil 283 of the control relay CR and conductor 284 tothe negative conductor 39. As soon as the interlock drum ID passes beyond its position e, a plurality of contact segments 285 and 286 that Vrespectively correspond to contact segments 247 and 239 engage control lingers 290and 29,3,` whence one circuit is completed through conductor 291, cooperating contact member 2920i the control relayv CR its upper or closed position, interlock G1out and thence through the off coil in accordance with a circuit that has liereinbefore been traced, While the other circuit is completed from control linger 293 through conductor 294, coperating contact members 295 of the control relay, conductor 242 and thence through the actuatingv coil On as previously set forth.,

Vhen the controller PK'occupies its position f, the control finger 245 engages contact segment 285 and vthe control lingers 272 and 240 still engage the contact segment 239. i i

UponA actuation of the master controller to its'position g', the-contact segment232 engages control nger`233, whence the control 'inger'244 is'K energized' to complete thel circuit of the actuatingtcoillOifmandthus' permit movement of the controlleriPKtoits ,position g, whereinthe control lingersv 272 and 240 become disengagedfrom contact segment 239 and control lingers 238 and 293 engage contact segment 286 to maintain Athe energization of the On actuating coil.; j

Upon movement of the master controller through its positions 71,', i" and j,th`econ trol ngers 166, 149 and 255 A,are successively energized, 'thus completing the correspond! 'nig circuits to permit a corresponding stepby-step actuation offthe controller PK. In the final position. lc of the 'master controller, the contact segment232 engages control finger' 62,- whence circuit completed ico through conductor 64 as herelnbefore described, contact member 301,A ,of the change over switch CO, conductor 302 and control finger 303V which engages contact segment 285 and thus effects the movement of the controller PK to its final position 7c.

As previously mentioned, thejoregoing description considers the case wherein the regenerative'machines are operated at a relatively high speed so that initialparallel regenerative operation is permissible.

However, if the speed o 'f the machines is suihci'ently low to preclude the possibility of employing parallel connected regeneration even though the controller PK is actuated lto its linal parallel position c to fully eX- Icite the main field windings, the further movement ot the master. controller MCyvill effect the energization of the control relay and, consequently, of the actuating coils on and ofi' and thus effect a step-by-step movement of the controller PK until the voltage across the series-related main armatures preferably exceeds the supply-circuit voltage by a predetermined amount, whereupon the relaydevice will be actuated to its proper position to close the line switch LS1 in accordance with' the previously traced circuits, and regeneration will take place from that point on tothe final position of thef'controller PK, in the manner already described.

As will be understood, the use of my fieldwinding current relay l is not as essential tc properoperation at the beginning of series regeneration as it was during the initial parallel regenerative period, by reason of the material dii'ercnce in machine speed andthe consequent removal,.to a considerable degree, of the above-mentioned undesirable occurrences, such as too heavy a rate of retardation;

Although I have shown and described my field-.Winding current relay ll in connection withfa certaintype-of system that is more or less complicated, it is believed that a materially simpler set o'fcircuit connectionsl would not fully set forth all the advantages accruing-from the use of my invention.

I do not wish to be restricted to the specific circuit connections` and arrangement andl location of partsherein kset forth, as-

various modiicationsthereof may bel effected withoutdeparting from the spirit and scope oli-my -invention `and I desire, therefore, that-onlysuch limitations shallbe iin- Aposed as are indicated in the appended claims.- j

I claim-Vas my invention l; In a system of control, the combination with a supply circuit and a dynamo-electric vmachine'having an armature winding and a'fieldwinding, of means for separately'exciting one of said windings, means for connecting themachine to the supply circuit, and means for automatically preventing further operation of thefsystem until the current in the separately-excited winding has attained a predetermined' value.

2; In a system of control, the combination with a supply circuit and a dynamo-electric machine having an armature winding and a field` Winding, of meansfor separately exciting one of said windings, means for automatically connecting the machine to the supply circuit under predetermined voltage conditions, and means for preventing further operation of the system until the current in the separately-excited winding has attained a predetermined value.

3. In a system of control, the combination with a supply circuit and a dynamo-electric machine having an armature winding and a field winding, of means for separately eXciting one of said windings, means forconnecting the machine to the supply circuit, a main-circuit resistor, and means for varying the active circuit value of said resistor only after the current in the separately-excited Windng has attained a predetermined value.`

i. In n, system oi4 control, the combination with a supply circuit and a dynamo-electric machine having an armature winding anda field winding, ofl means forl separately exciting one of saidwindings, means `for connecting the machine to the'supply circuit, a-

main-circuit resistor, switches-for excluding certain sections of said resistor from circuit, means dependent upon the value of current in the other of said windingsforefi'ectingthe gradual closure of said switches, and means for rendering said last means inoperative until the current inthe separatelyexcited winding has attainedz a predetermined value. Y I 4 l 5. Ina system-of control, the'combinationl with a supplycircuit and a dynamo-electricV machine having an armature winding and a. f ield winding, of means for separately eX'- citing said field winding, means fon connecting the machine tothe supply circuit, and means for l automatically, `preventing I furthery operation of the system untilf the field-winding current has attainedY a. predetermined' Vflll. ,el .'-i.- n

l 6. Ina system` 'of controhfthe,combination with a supply circuit anda dyinainn-.electric machine V.having an armature winding anda p field winding, of means forf'separately 'en 4 citing saidv eld, winding, v.means 4for auto-.lf

maticall-y. connecting the machine to the supply circuit under predetermined voltageA conditions, and means for automatically. preventing further operation of the system,

citing said held winding, means forvconnect-, ing the machine to the' supply lcircuita re-, sistor initiallyconnected in circuitwith said; machine, andj means-for gradually excluding said resistor from circuit Vorilygafter the,y field-windin current has attained apredJe-v.

termined va ue.

8. In a system of control, the combination with a supply circuit and a dynamo-electric machine having an armature winding and a field winding, of means for separately eX- citing said field winding, means for connecting the machine to the supply circuit, a resistor initially connected* in circuit with said machine, switches for excluding certain sections of said resistor from circuit, means dependent upon the value of current in said armature for eecting the gradual closure of said switches, and means for rendering said last means inoperative until the fieldwinding current has attained a predetermined value.

iio

9. In a system of control, the combination with a supply circuit and a dynamo-electric machine having an armature windin` and a eld winding, of means for separate y exciting said ield winding, means for connecting the machine to the supply circuit, a resistor initially connected in circuit with said machine, electrically-controlled switches for excluding certain sections of said resistor from circuit, a limit switch energized in accordance with the armature current for effecting the gradual closure of said switches, and a relay device connected to complete the circuits governed by said limit switch when the field-winding current attains a predetermined value.

10. In a system of regenerative control, the combination with a supply circuit and a .momentum-driven dynamo-electric machine having an armature winding and a iield winding, of means for supplying additional current to said field winding, means for connecting the machine to thesupply circuit, aresistor initially connected in circuit with said machine, switches for exclud-v ing certain sections of said resistor from circuitswitching means dependent u on the value of Aregenerated current for e ecting the I' gradual'closure of said switches, and

means -for rendering said switching means inoperative until the field-winding current has attained a lpredetermined value.

11. In a system of regenerative control, the combination with a supply circuit and a momentum-driven dynamo-electric machine having an armature winding and a field winding, of means for supplying additional current to said field winding, means for automatically connecting the machine to the supply circuit under predetermined voltage conditions, a resistor initially connected in circuit with said machine, -switches for excluding certain sections of said resistor fromcircuit, actuating coils for said switches, a limit switch energized in accordance with the armature current and embodying con- J tact members for successively effecting the energization of said actuating coils, and aV relay device energized in accordance with the field-Winding current and embodying cooperating contact members that are connected to complete the circuit through said other contact members when the field-winding current attains a predetermined value.

l2. In a system of control, the combination with a supply circuit and a dynamoelectric machine having an armature and a eld winding, of means :for separately exciting said field winding, means for connecting the machine to the supply circuit, means for automatically preventing further operation of the system until the field-Winding current has attained a predetermined value, and means for subsequently governing the system in accordance with the regenerated current.v` V

13.'In a system of control, the combina- I' tion with a supply circuit and a dynamoelectric machine having an armature winding and a field winding, of means for separately exciting said field winding, means for automatically connecting the machine to the supply circuit underpredetermined voltage conditions, means for automatically preventing further operation ofthe system until the field-winding current has attained la predetermined value, and4 a limit switch for subsequently governing the system in accordance with armature-current conditions.

'14. In a system of control, the combination with a supply circuit and a dynamoelectric machine having an armature Winding and a field winding, of means for separately exciting said eldwinding, means for connecting the machine to the supply circuit, a resistor initially connected in circuit with said machine, and means for gradually excluding said resistor from' 'circuit only after the field-winding current and the regenerated current have attained respectively'predetermined values.

In testimony whereof, I have hereunto subscribed my name this 29th day of November, 1916. i

'CHARLES C. WHITTAKER. 

